Both myself and some of my users have this question:

I have multiple personal calendars, based on the project that the events are for. If I create a new appointment, I can select which calendar it goes onto, so it is colored correctly and I can select/deselect viewing for that project.

However, if someone else on the team creates an appointment, I am not sure how to either:
1) Pick from a dropdown where the appointment ends up
2) Move it from one calendar to another once it is accepted

Where are these options in the UI? It seems that I can only accept into the default calendar and can't move it, which defeats the purpose of having multiple calendars!